Fault characteristics analysis for rotor systems with misalignment based on Wavelet Packet Decomposition and frequency-band energy ratio analysis

In this paper, combining with model experiment, fault characteristics of single-span and dual-disc rotor system with bearing misalignment are investigated by the combination of Wavelet Packet Decomposition (WDP) and frequency- band energy ratio analysis method. Firstly, resampling is applied to ensure the accurate and efficient decomposition of signal frequency-band. And then with the mother wavelet function ‘db44’, the displacement signals were decomposed into 4 levels. Moreover, through a comparison with the time-domain waveforms and amplitude spectrums of decomposed signals in different decomposing levels, the effects of different misalignments to system vibration are shown. And corresponding frequency-band energy ratio values can have an excellent corresponding relationship with the misalignment degree and actual speed which can be applied to fault feature extraction to implement effective diagnosis of misalignment fault.

[1]  K. M. Al-Hussain,et al.  Dynamic stability of two rigid rotors connected by a flexible coupling with angular misalignment , 2003 .

[2]  Fulei Chu,et al.  VIBRATION SIGNAL ANALYSIS AND FEATURE EXTRACTION BASED ON REASSIGNED WAVELET SCALOGRAM , 2002 .

[3]  Peter W. Tse,et al.  Detection of the rubbing-caused impacts for rotor–stator fault diagnosis using reassigned scalogram , 2005 .

[4]  Qingkai Han,et al.  Vibration Fault analysis for rotor systems by using Hilbert spectrum , 2010, 2010 International Conference on Mechanic Automation and Control Engineering.

[5]  Qingkai Han,et al.  Characteristics of variable parameters in rotor system with rub-impact fault , 2010, 2010 8th World Congress on Intelligent Control and Automation.

[6]  Bangchun Wen,et al.  EXPERIMENT OF OIL-FILM WHIRL IN ROTOR SYSTEM AND WAVELET FRACTAL ANALYSES , 2005 .

[7]  Shuai Zhang,et al.  Rub-impact fault vibration analysis of rotor system with the different parameters using Hilbert-Huang transform , 2010, ICMIT: Mechatronics and Information Technology.

[8]  I. Redmond,et al.  DYNAMIC RESPONSE OF TWO ROTORS CONNECTED BY RIGID MECHANICAL COUPLING WITH PARALLEL MISALIGNMENT , 2002 .

[9]  J. S. Rao,et al.  Vibratory Condition Monitoring of Machines , 2000 .

[10]  P. D. McFadden,et al.  APPLICATION OF WAVELETS TO GEARBOX VIBRATION SIGNALS FOR FAULT DETECTION , 1996 .

[11]  W. J. Wang,et al.  Application of orthogonal wavelets to early gear damage detection , 1995 .

[12]  Fulei Chu,et al.  Application of the wavelet transform in machine condition monitoring and fault diagnostics: a review with bibliography , 2004 .